Construct BST from given preorder traversal

PROBLEM :

Given preorder traversal of a binary search tree, construct the BST.

For example, if the given traversal is {10, 5, 1, 7, 40, 50}, then the output should be root of following tree.

     10
   /   \
  5     40
 /  \      \
1    7      50


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SIMPLE c++ IMPLEMENTATION :
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/*
typedef struct BST
{
int info ;
struct BST *left ;
struct BST *right ;
}tree ;                       */

tree *construct_preorder_BST(int [],int ,int ) ;

tree *BSTree_preorder(tree *root)
{
int a[100],i,no ;

cout<<"\n enter the size of the array" ;
cin>>no ;
cout<<"\n enter elemets " ;
for(i=0;i<no;i++)
cin>>a[i] ;

root=construct_preorder_BST(a,0,no-1) ;
return root ;
}

tree *construct_preorder_BST(int a[],int start,int end)
{
if(start>end)
return NULL ;
tree *temp ;
temp=(tree*)malloc(sizeof(tree)) ;
temp->info=a[start] ;

int i ;
for(i=start+1;i<=end;i++)
{
if(a[i]>a[start])
break ;
}
temp->left=construct_preorder_BST(a,start+1,i-1) ;
temp->right=construct_preorder_BST(a,i,end) ;

return temp ;
}


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